NL2006020C2 - CONSTRUCTION WORK, IN PARTICULAR HORTICULTURAL GREENHOUSE WITH A SYSTEM FOR ABSORBING SUNLIGHT. - Google Patents

Abstract

The invention relates in particular to a greenhouse of the "Venlo" type, comprising a framework (1-3) for supporting at least a roof structure. Said roof structure is provided with at least one, preferably asymmetric, roof section comprising a substantially south-facing south deck (5) and, adjoining said south deck, a north deck (6). The north deck and south deck are bounded by a gutter (7) on one side and by a higher-positioned ridge (8) on the opposite side. The north deck is provided with panes and air windows (19) and the south deck is provided with at least two, preferably linear, Fresnel lenses (10, 11) disposed between the gutter and the ridge, each Fresnel lens having associated absorption elements (12, 13) provided therebelow, which Fresnel lenses are arranged for tracking, with at least two degrees of freedom, the position of the sun by means of a moving mechanism (14) connected to the absorption elements. The invention provides, inter alia, a special moving mechanism, whilst also the constructions of the Fresnel lenses, the absorption elements and the panes are innovative.

Description

NL 15203-Me j

Construction work, in particular horticultural greenhouse with a system for the J

absorbing sunlight

The invention relates, inter alia, to a building, in particular a "Venlo" type greenhouse, with a skeleton for supporting at least one roof construction, which roof construction is provided with at least one, preferably asymmetrical, canopy with a south deck that is oriented substantially south to the yy and a subsequent north deck, which j

north deck and south deck on one side are bounded by a gutter and on an opposite side are bounded by a higher I

empty ridge, wherein the north deck is provided with windows and aeration windows and the south deck is provided with at least two; Fresnel lenses, preferably linear, placed between the gutter and ridge, with each associated and arranged mount. elements adapted to follow the position of the sun with at least two degrees of freedom with the aid of a movement mechanism coupled to the absorption elements, i.e.

provided with traction cables, the absorption elements being suspended from adjustable suspension cables (r-cables) which extend from the absorption elements at least approximately along the axis of the associated lenses to the south deck and therefore adjust the distance to the lenses upon adjustment, while at least I

another adjustable cable (kabel cable) to the north deck

runs and adjusts the angle φ between the vertical and the r-cable when adjusted.

Such a horticultural greenhouse is known from the public report of the Wageningen UR Greenhouse Horticulture, entitled "Fresnel concentrating systems for horticulture", Note 604 of February j 2009. In Fig. 4.2, a movement mechanism with cables j is shown for the purpose of moving 3 absorption elements. Two kabels-cables are arranged here, one of which is connected to the absorption element that is closest to the north deck and runs towards the north deck, while the other φ-cable is connected to the absorption element farthest from the north deck and goes to the south deck and is weighted there. The absorption elements are interconnected by a cable. The disadvantage of this construction t j 2! is that the forces in the movement mechanism become very large because in the extreme positions of the absorption elements the The angle between one of the φ cables and the r cables is approaching 180 °, whereby an increasingly smaller part of the tensile force can be controlled! 5 usefulness for eliminating gravity and therefore the tensile force in the φ-cable must become increasingly larger that for a large part must be absorbed by the r-cable. j

SUMMARY OF THE INVENTION It is an object of the invention to provide a movement mechanism for the absorption elements according to a first aspect, wherein the play of forces is improved, in particular in the extreme positions of the absorption elements, and which takes up no space on the north deck.

To this end, the horticultural greenhouse according to the invention is characterized in a first aspect in that at least a part of the absorption elements through a pressure-rigid connection to; a unit are connected to each other and the φ cable to the one! engages a location at a distance from the absorption element that is closest to the north deck.

Because the absorption elements are connected by a rigid connection, it is made possible for the kabel-cable to be disconnected. engages a lower position on the unit, for example in the case of 2 absorption elements in the vicinity of the lowest absorption element, whereby the angle between the φ-cable of the north deck and the r-cable becomes smaller and thus the tensile forces in the cables decrease, resp. the absorption elements can be adjusted to a more extreme position, that is, closer to the north deck. Preferably, the φ-cable at the north deck effectively engages in such a place that in all 5 positions of the absorption elements the angle between the horizontal [30 and this effective engagement direction] is at most 50 ° and the angle between the r-cables and this effective engagement direction is a maximum of 140 °. The force in the r-cables must thereby be between 0 (the absorption elements must also not hang on the kabel-cable, because otherwise the r-35 adjustment will be disturbed) and maximum operating load of the cables, for example 100 kg with a 3 mm steel cable.

In an advantageous embodiment, the kabel-cable runs from a position near the cap of the cap to a pulley on the one

3 I

the absorption elements and extends them to a lower location on or below the north deck.

In this way the effective engagement point on the north deck moves, such that a favorable i

5 force distribution is maintained. The construction is cheaper and simpler than, for example, a single I cable I

movably engage on the north deck, which of course is possible. Furthermore, this "double" version j

of the φ-cable the advantage that one cable part is always J

10 can be above the pressure-rigid connecting part and the upper absorption element and the other part below it, whereby no restrictions are imposed by the upper absorption element.

It is favorable if the kabel-cable runs from the unit to a pulley on a column below the north deck, because the forces can easily be absorbed in the column and the cable can be moved further from the column to a drive. lead.

For the reception of light in the absorption elements, it is favorable if the absorption elements are arranged so as to always be directed in the direction of the heart or the symmetry line of the lens, the absorption elements each separately are attached to one of the r-cables and rotatably connected to the pressure-rigid connection between the absorption elements. It is very advantageous if the drives for the jr and φ cables are each attached to one of the horizontal trusses or other horizontal components. This makes it possible to use techniques which are already known, since the drives for air vents, light screens and the like are also usually attached to trusses. The air vents preferably consist of sliding windows, the drive of which is arranged on the north deck, so that the trusses are free for the drive of the r and kabels cables. j

With the horizontal truss, the kabel-cable can be diverted through 180 ° to a pulley movable parallel to the φ-cable and connected to the associated drive. This way ! the adjustment path is halved, which makes it possible to adjust the j i

φ cable can be doubled as described above, without I

[ί 4! This causes a too large adjustment path on the horizontal trusses or other horizontal structural parts. j

In the case in a direction parallel to the cam of I

If a hood has a number of horizontal trusses arranged parallel to each other, it is advantageous if at least a part of the the trusses, and preferably with all trusses, the absorption elements are provided with r and kabels cables and associated on | drives on the horizontal trusses, wherein the drives of a number of horizontal trusses are mutually coupled and are adjusted with a single drive motor.

A simple embodiment is that in which the drives on the horizontal trusses are equipped with racks that are connected with the associated cables, and with gears that engage with the associated racks and are mutually coupled by a torsionally rigid shaft rotatable by the relevant drive motor. is.

In case the horticulture greenhouse comprises a number of connecting caps, it is favorable if the drives for the r and φ cables of a number of caps are mutually coupled.

In this way, a single drive motor, in particular

without electric motor, drive a whole field of movement mechanisms, the drive motor preferably being arranged near the center of the field, in order to minimize torsional forces and the like.

It is favorable if the ratio of the width of the Fresnel lenses in the direction between the gutter and the cam and the focal length (focus) is a maximum of approximately 0.85, and preferably between! approximately 0.66 and 0.82. With a larger ratio, the efficiency (the amount of light that falls annually on a defined focal length: the amount of light that falls on the Fresnel lens) decreases rapidly. The average (diffuse and direct) light transmission also decreases with a larger ratio. With a smaller ratio, the "top piece" or "top piece" (the space above the horizontal truss) of the horticultural greenhouse becomes relatively j

35 are too large and the absorption elements must make large swinging movements. The higher upper part could also be avoided by I

apply a larger number of smaller Fresnel lenses, but then the number of focal lines and thus absorption elements increases; making the cost considerably higher. Moreover, the absorption elements then become very narrow and vulnerable.

The height of the upper part of a Venlo greenhouse is determined by the length of an extension column, that is, the distance between the truss and the trough. With normal greenhouses: · the gutters are approx. 15 to 20 cm above the truss on very short mounting columns. In the case of the use of 2 Fresnel lenses between the gutter and ridge of the south deck (and thus 2 absorption elements), j is preferably the ratio of column length: length of fire <10 point distance between 0.6 and 1.1. In a very specific version j

that ratio is 1.65: 1.875 = 0.88. The length of the mounting columns above the frame is then 165 cm. There is then a sufficiently free "empty" space above the frame around the movement mechanism

to release and release the absorption elements I'm moving. From the truss down, the greenhouse can again be one! "normal" greenhouse, where all standard facilities can be made.

The Fresnel lenses, at least in the direction between gutter and cam, are preferably formed from a number of elements formed with the aid of casting molds. This takes the price of the! considerably decrease. The total price for the molds can decrease even further if the Fresnel lenses are formed from a number of pairs of elements which are arranged mirrored with respect to the plane of symmetry or the axis of the lens. The number of required molds is thus halved. j

The Fresnel lenses are preferably between glass plates I

of a window pane, such that the grooves that form the lens face upwards. The Fresnel lenses are protected in this way by the glass plates and it is possible to turn the grooves 30 of the Fresnel lenses upwards, without having problems with contamination of the grooves. If the Fresnel lenses j consist of individual elements, they can be assembled in the factory with the glass panes into one unit, so that assembly in the work can be limited. If a number of elements of a Fresnel lens are placed between two glass plates, these elements are preferably provided at least on the top and bottom edges with a ridge projecting transversely to the element, which protrudes preferably to the bottom and top. y 6 y y y

Through these ridges it is possible to place the elements of the Fresnel lenses loosely between the glass panes, whereby the rows

chels prevent the elements from sliding past each other if the space between the glass plates is greater than the thickness of I

5 two elements. This space between the glass plates and the lens element

on the contrary, it is favorable because then the insulation value of the I

composite glass plates increases. Due to the ridges on the lens elements, the lenses are also separate from the glass plates, so that no damage to the surfaces of the lenses will occur! 10 arise. 1

S

If the lens elements are formed by injection molding, the ridges, which are then preferably arranged over the entire circumference, also have the function of considerably reducing the warping of the lens elements during cooling. Furthermore, the lens elements can be provided at the edges, preferably near the corners, with stacking members, such as protruding legs on at least one side for cooperation with the ridges.

In this way it is possible to stack the lens elements automatically after forming, while it is not necessary to provide the lenses with protective film because the lens surfaces are kept at a distance from each other. This saves considerably on handling costs. i

The Fresnel Lenses j

25 (also) in the direction parallel to the cam from a number of ele-S

and the elements of the Fresnel lenses are formed on their opposite side edges with form-fitting connecting members such that in the direction parallel to the cam; neighboring elements are connected to each other in a tensile and sliding manner.

The surfaces of the glass plates and the surfaces of the lens elements can be provided with an anti-reflection coating to minimize the reflection at the transitions from air to glass and vice versa. It is most effective to have the "dry" surfaces, i.e., those in the cavity between the j

provide glass plates with the coating because the efficiency of J

the coating reduced by moisture. j

If the north deck has sliding windows, it is | favorable if the north deck is in a position above the opening of j | 7 the sliding windows are provided with a (transparent) rain cover that extends diagonally downward from the north cover at an angle with the north cover to a free end, the rain cover preferably being curved and the angle of the rain cover having the north cover increases toward the free end.

Such a rain cap has, in addition to its normal function of preventing rain, a further function of making the aeration more controllable. Normally it is difficult to accurately control the aeration at small openings of the air window. The position and course of the rain cover with respect to the north deck can be chosen such that the gap between the rain cover and the sliding window determines the ventilation opening and not the gap between sliding window and frame. For a good aeration control, the change in the gap between the rain cover and the sliding window when the sliding window is moved can be designed by the position and design (of the rain cover).

The angle of the south deck with the horizontal is preferably between 10 ° and 40 ° and is (in the Netherlands) preferably approximately 30 ° (90 ° minus the maximum sun height which is + 60 ° in the Netherlands). a more southern country with a maximum sun height of approx. 70 ° this would be 20 °, while the north j

cover is at least approximately perpendicular thereto. The energy yield I

is then maximum and the light distribution on the ground is uniform, that is to say no or hardly any disturbance due to direct sunlight incident through the north cover in high summer.

The absorption elements are preferably provided with a number of PV modules with PV cells.

In an embodiment of the horticultural greenhouse in which a number of parallel glass rods are distributed over the length of the hood, the length of the PV modules preferably corresponds to the distance between the glass rods, wherein the PV cells within a PV modules are connected in parallel and the adjacent PV-j modules are connected in series. This embodiment has the great advantage that the inevitable shadow that the glass rods will cause does not have a major negative effect on the efficiency of the series connected. | PV modules. In a series connection, the maximum current is determined by the current through the worst PV cell

δ I

and that is the PV cell that is in the shade. Now that the length of the PV modules corresponds to the distance between the glazing bars, shadow will always fall on the same PV cell (s) in all PV-j modules. Because the PV cells within a module are connected in parallel, a "shadow" cell has the same (slight) effect! the yield of all PV modules, which are therefore not affected by each other in their series connection, as a result of which the efficiency is not adversely affected. j

An installation-technically advantageous embodiment is that in which the absorption elements are designed with carrier profiles welded together in the work, on which the PV module is placed, preferably with the aid of adhesive strips, wherein the adjacent PV cells are within a PV modules are provided with terminal poles protruding transversely to the length of the PV module, with adjacent PV modules positioned alternately, such that with adjacent PV modules the plus poles of one PV module protrude to the same side as the corresponding minus poles of the other PV modules and thus one over the | The length of two adjacent PV modules is connected to a continuous conductor with all of the adjacent and protruding poles of the adjacent modules, whereby the PV modules are connected in a current-conducting manner. An embodiment in which the current is discharged on both sides of the cell j is also possible. The + and - poles are then alternately 25 and there are + and - a current drain conductor per side. j

The carrier profiles can be accurately aligned to each other at work. The PV modules can there! simply be attached to these carrier profiles. Thanks to the special poles of the PV cells and the alternating mounting of the 30 PV modules, the PV modules can be connected relatively easily to each other in series, without the need for expensive and sensitive plug connections. connections between the PV modules are required. This saves considerable costs.

A very simple connection between the PV modules 35 is achieved if the current conductors are attached to the PV modules by means of click profiles, preferably in that each pole and the current conductor are clamped together by the click profiles. A good and lasting contact is guaranteed in the click profiles if they are provided with pressure elements, j j j j i j i

9 I

such as a molded leaf spring, neoprene rubber lace and the like, for keeping the current conductors in contact with the poles. In the case of aluminum conductors, these are coated, silver-plated or tin-plated at least at the location of the contact.

5 To be in a versatile version of the greenhouse!

absorption elements on both sides provided with light scattering elements, such as scattering glass or Fresnel lenses for daylight control.

In this embodiment, it is possible to utilize the absorption elements as stepless daylight control by making the absorption elements higher or lower than the focal line.

positioning. Part of the light beam will then be the absorption I

! elements pass. This will normally lead to light and dark | smaller stripes on the ground, but the light-scattering elements scatter the light in such a way that a more or less uniform exposure of the ground takes place.

In a special embodiment of the horticultural greenhouse, the drives for the movement mechanism for the absorption elements can be controlled by a position of the sun tracking system, which tracking system is provided with at least two rows of light-sensitive sensors which extend substantially transversely to and in the light beam, wherein the rows are arranged at different distances from the lens, and from measuring means capable of measuring and receiving the amount of light received from the sensors

Identification means which can calculate at least the direction of the light beam from the light measurements in the two rows and preferably also the distance of the focal line, and the tracking system therewith can control the drives for keeping the absorption elements in the focal line.

The movements can be controlled by this position of the sun position; of the movement mechanism for moving the absorption elements when changing the position of the sun are considerably reduced, thereby reducing the energy consumption of the drives and the yield of the absorption elements. 35 elements is increased because they are always kept well in line with the Fresnel lenses. ! i

Preferably, the rows of photosensitive j.

sensors staggered with respect to each other in a direction parallel to the focal line, preferably over a distance of; 10 j more than 3 times their mutual distance in the direction of the j lens, for example if one row of photosensitive sensors is at a distance of about 2 - 10 cm above the absorption elements and the other row of sensors at a distance placed 10 cm above the absorption elements, the rows i of photosensitive sensors are offset over a distance of more than 30 cm, and preferably over the center distance of the rods (1.25 m) or more.

Further features and advantages of the invention follow from the description below with reference to the drawings which schematically represent an exemplary embodiment of the invention.

FIG. 1 is a cross-sectional view of a small greenhouse for the sake of clarity. FIG. 2 is a schematic perspective illustration of the operating mechanism for the absorption elements from the greenhouse of FIG. 1. 1

FIG. 3 shows a portion of the greenhouse of FIG. 1 on a larger scale.

FIG. 4 is a top view of the drive for the operating mechanism of FIG. 2 and 3.

FIG. 4A and 4B are details IV A and IV B in FIG. 4 illustrating the play of forces in the drive of the cables of the movement mechanism of the absorption elements of the greenhouse. j

FIG. 5 and 6, respectively. 7 and 8 are shown in FIG. 3 corresponding views, wherein the operating mechanism and drive are shown in two other positions. |

FIG. 9 is a perspective view of a portion 30 of the drive for a number of movement mechanisms in multiple hoods of the greenhouse of FIG. 1.:

FIG. 10 and 11 show the detail X in FIG. 3 in two different positions. |

FIG. 12 is a perspective view of a number of air vents from FIG. 10 with the movement mechanism therefor.

FIG. 13 is a very schematic perspective view of two Fresnel lenses with associated absorption elements in a stand such as this is built into a greenhouse. j {j i f i ί

11 I

FIG. 14 is a larger-scale sectional view according to detail XIV in FIG. 3. |

FIG. 15, A, B, C are a top view, section along the line C-C in FIG. 15A, and front view of the lens element A of FIG. 13 on a larger scale. 1

FIG. 16 are A, B, C with FIG. 15 matching arrivals! views of lens element B of FIG. 13.

FIG. 17 A, B shows details XVII A and B in FIG. 15. | FIG. 18 shows detail XVIII on a larger scale, where | it is furthermore illustrated how a number of lens elements are stacked on top of each other. | l

FIG. 19 is an exploded perspective view of a | part of the absorption element of FIG. 3. FIG. 20 illustrates the electrical diagram of the PV! cells of the absorption element of FIG. 19. j

FIG. 21 shows detail XXI in FIG. 19.

FIG. 22 is a larger-scale cross-sectional view of another embodiment of the absorption element 20 according to the invention.

FIG. 23 is a larger-scale, partially sectioned perspective view of a suspension of an absorption element, as shown in FIG. 3. [

FIG. 24 is one with FIG. 3 comparable view of the I

25 horticultural greenhouse, in which a sensor for a solar tracking system is arranged.

FIG. 25 is a schematic representation of the operation of the sensor of FIG. 24. The horticultural greenhouse according to this exemplary embodiment of the invention is constructed with the aid of a number of vertical columns 1 and horizontal trusses 2 attached thereto, as well as auxiliary columns 3 supported by the trusses. These columns and trusses support a roof structure. | Construction 4 with a number of caps, which are asymmetrical, each having a south deck 5 and a north deck 6. These expressions south and north deck assume that they are placed on the northern hemisphere, where the sun is in the south. On the

12 I

in the southern hemisphere, the situation will be the other way around, and the terms north and south should be read the other way around. j

These south decks 5 and north decks 6 each time extend between a trough 7 at the location of a column 1 or 3 and j

5 a higher ridge 8. Glass carriers or rods 9 form the distance I

bindings between gutters 7 and cams 8 and support glass panels which are still to be discussed that form the roof covering. The greenhouse deck is a so-called Venlo deck: apart from the aluminum glass supports, the gutter and the ridge, there is no longer any construction in the deck (such as; 10 for a wide-roof greenhouse, where there is a truss around the compartment and there! are also purlins again). The horticultural greenhouse shown is in principle designed to be placed with the south decks 5 on; facing south (150 ° ^ azimuth ^ 210 °; if! azimuth south = 180 °). The asymmetrical design has the advantage that the energy yield is maximized (more 'greenhouse surface area participates) and that there is a more even light distribution at plant height (no strips of light through the north cover)

The greenhouse cover in this case consists of one roof 4 m wide (center-to-center distance between gutters 7), the south deck being at an angle of 30 ° and the south deck having a length from gutter to ridge of about 3.13 m. This contains (in cross section) two linear 1

Fresnel lenses 10, 11 (see Fig. 3) each approximately 1.54 m wide (in the direction between gutter and ridge). The Fresnel lenses 10, 11 have a design focal length of 1.875 m. Each Fresnel lens 25 cooperates with an absorption element 12 and resp. 13 that can be moved with two degrees of freedom] to follow the focal line during the sun's movements.

The width of the lens: focus distance = preferably j

30 at most 0.85 (1.54: 1.875 = 0.821). With a larger ratio (for example 1.05), the efficiency (the amount of light that falls on a defined focal length each year: the amount of light that falls on the lens) drops quickly. Also the average I

(diffuse and direct) light transmission decreases with a larger ratio.

With a smaller ratio, the "top piece" or "top piece" (the space above the horizontal truss 2) of the greenhouse becomes

relatively too large and the absorption elements 12, 13 must make large swinging movements. The higher upper part would also avoid 13! .

can be applied by using more smaller lenses, but then the number of focal lines and thus absorption elements increases, so that the |

cost becomes higher. Moreover, the absorption elements then become very small and vulnerable. J

The chosen geometry is more or less an optimization of the construction (a not too large cap voltage, glass size, aluminum rod), yield of energy harvest (a not too strong! Lens), and costs (not too many lenses and therefore costs of absorption elements). The space between the north deck 6 and the trajectory of the highest absorption element is also a technically usable distance (with more absorption elements this becomes proportionally smaller, while the construction always maintains a minimal or practical dimension).

In the longitudinal direction of the cap, i.e. parallel to the cam 8, the linear Fresnel lens 10, 11 could be infinitely long, in practice this length is limited by the width of the panes, i.e. the center-to-center distance of the rods (in this case 1.25 m, but this could also be 1.67 m).

Incidentally, it is easiest if the compartment size (center distance of the horizontal trusses 2) is a multiple of the center distance of the panes: in this case, 5.0 m compartment size: 1.25 is 4 panes in one! field.

As stated, the absorption elements 12, 13 must be provided with a movement mechanism 14 in order to keep the absorption elements in the focal line of the Fresnel lenses when changing the position of the sun. The position of the sun changes both during the day (azimuth) and during the year (sun height). j

Each movement mechanism 14 is provided with cables, two types of cables, namely so-called r-cables 15, 16 extending from the absorption elements 12, 13 to the center of the associated lens 10, 11, and a so-called cp cable 17 this extends from the absorption elements 12, 13 to the north deck 6.

These cables have a minimal light interception, and can be changed in direction by means of pulleys, as a result of which cables can easily be constructed compactly, while the costs are relatively low. The absorption elements 12, 13 have two degrees of freedom through the cables which are conceived as polar coordinates (r, cp) with the center of (one of) the lenses as an axial cross (0,0). | i · j 14 y

In connection with the asymmetrical deck, there is little construction space on the north deck 6 to "pull over" the upper absorption element 1 (the φ-adjustment). Moreover, the movement mechanism 18 for an air window 19 must also be installed here. .

It therefore gives many advantages to the upper absorpj

element 13 (that at the north deck 6) cannot be pulled aside, I

but to push from below. He can then (almost) withstand the j

north deck 6 are pushed. The kabel cable 17 is therefore not connected to J

10 the upper, but attached to (or near) the lower absorption element 12 (in the case of 2 absorption elements). A concession is hereby made to the light interception and the costs, because a connection between the two modules must then be a pressure-rigid connection, for example a pressure rod or tube instead of a traction cable. In addition, a stabilizing cross-over 54 must be provided between the upper and lower absorption elements 12, 13 once per coupled unit of the absorption elements (preferably in the middle of the coupled unit), since the stabilization no longer starts from 20 the force of gravity is guaranteed (the upper absorption element 13 "stands" with the push rod 20 on the lower 12 and is therefore in principle unstable), as in the prior art with the wires hanging below j via the upper absorption element lower | absorption elements was the case.

Another problem is that due to the required r-adjustment j

of the absorption elements 12, 13 actually not a good "draw point" I

for the φ-adjustment can be found: If the draw point in the cam 8 is selected (i.e. high), the tensile force in at least the r-cable 15 can become negative in low positions of the absorption element 12, 13 (i.e. a compressive force) , because the absorption element 12 is pulled up by the φ-cable 17). If the draw point at the channel 7 is selected (i.e. low), the tensile force in the cables 15 and 17 j can become too great in high positions of the absorption element 12, 13, because the angle between these cables becomes too large.

Moreover, it is physically impossible in combination with tension cables to make this angle greater than 180 °, as a result of which an entire area cannot be reached. So an adjustable draw point j is actually required, roughly flush with the r-adjustment. As said, there is little room for this at the north deck 6, but it is also technically complex to realize. The thread in question may not cross the absorption element 13 in some positions: it must therefore always remain above the pressure rod 20 or always remain below it.

This has been solved by moving a fictitious moving with the aid of a pulley 21 at the location of the lower absorption element 12; "pull point" along the north deck 6, which is always in a reasonably optimal place in relation to the direction of movement desired at that moment. The forces in the cables 15 - 17 therefore always remain within limits and never become negative, the cable parts of the φ-cable 17 never cross the module (the upper cable part is always above the push rod 20, the lower always below, the average fictitious cable and resulting tensile force is always directed approximately parallel to the pressure rod 20, in this embodiment + 20 ° above to -15 ° below the pressure rod).

As can be seen in, for example, FIG. 2 and 3, the r-adjustment takes place "to the left", and the φ-adjustment takes place "to the right": this means that the different cables 15, 16 and 17 do not encounter each other ® 20. The r-cables 15, 16 are guided via pulleys 22, 23 below the south deck 5 in the middle of the respective lenses 10, 11, to their own pulley 24 at the top of a column 1, 3, then to their own pulley 25 to the column at the height of the truss 2 and then to a drive 26 which is mounted on the truss 2. The r-adjustment of the one absorption element 12 is on one side of the "truss" rod 9 and columns 1, 3 ("for"), that of the! the other absorption element 13 is on the other side of the "truss" rod 9 and columns 1, 3 ("rear"). These cables 15, 16 therefore also do not meet. As a result, the forces from the cables 15 and 16 also engage symmetrically about the center of the tensile pressure tube 39, whereby minimal extra moments are exerted on the tensile pressure tube (Fig. 4A).

The kabel-cable 17 is, as said, from the cam (this can also be from a location near the cam) to the pulley 21 near the lower absorption element 12 and from there to a pulley 27 near the upper end from the "right" column 3, 1, then to a pulley 28 on this column at the height of the truss 2! and then guided to a drive 29 on the truss 2. The cp j adjustment is in the part above the absorption element 13 j i i!

16 I

"behind" the column 3 and in the part below the absorption element j "front", that is to say on the other side of the "truss" rod, then the r-j adjustment cable 16 of absorption element 13 and these therefore meet each other j neither against nor at the point where they intersect. In this embodiment the pulley 21 is placed in the center of the pressure rod 20 and directly under the clamping rod 9. The minimum forces parallel to the absorption element 12 caused by the oblique running away of the kabel-cable cancel each other out in that the top and bottom of the φ-cable run away to different sides of the clamping rod 9. As a result, undesired resultant forces are minimized.

Because the cables 15 - 17 are driven by the aforementioned drives 26, 29 on the truss 2, this means that the absorption elements 12, 13 are suspended around the shelf size of cables 15, 16 (because the drives lie on the truss that is tied to the profession size). Therefore, as described above, the section size must also be a multiple of the center-to-center distance of the rods 9, since the cables must be hung on something and in the case of a Venlo-like deck, the only construction material in the deck is the rod 20 in which the glass lies. . The rods 9 above the trusses 2 are therefore preferably weighted (for example by a steel U-profile around the rod or a strip in the rod, the circumference and thus the resulting shadow being equal to the other rods). !

As stated, a (small) tensile force must always be present in the cables (positions "left" of the vertical hanging ropes 15, 16 cannot therefore be achieved). Pressure forces are not possible. Too high tensile forces are undesirable in connection with a desired minimum cable thickness (at 3 mm, for example, the maximum tensile force is about 100 kg). The cables 15 - 17 are tensioned on the one hand by gravity (weight of absorption elements 12, 13) and on the other hand by the forces of the motors. Because the 2 motors can work against each other (with incorrect control), a cable force limiter is installed in one of the cables 15-17 per hoisting section (see also below). j

The cables 15 - 17 are prefabricated to the desired length with preferably cast-on eyes and preferably rolled I

threaded ends. Post-adjustment in the work is done through I

set swivels (set screws) arranged at the end of the wires on said wire ends. I

17 yrs

As stated, the drive 26 describes r, "while the drive 29 φ realizes. By opting for this construction it is achieved that the absorption elements 12, 13 are always directed towards the center of the respective Fresnel lenses 10, 11 i 5: the upper surface of the absorption element is therefore always optimally (= perpendicular) oriented with respect to the light cone that he must intercept / hold back. Figures 3, 5! and 7 show 3 positions of the absorption elements 12, 13 and the associated movement mechanism 14, which correspond to 3 positions 10 of the sun. For example, the positions correspond approximately to: j (Fig. 3, 4: midsummer around noon for all greenhouse orientations), i (Fig. 5, 6: in the spring or autumn around noon for all greenhouse orientations) and (Fig. 7, 8: midsummer early in the morning with a greenhouse orientation somewhat south-west or late in the evening with a greenhouse orientation slightly south-east).

By placing the pulley 21 on the lower absorption element 12, the kabel-cable 17 must describe a 2x larger stroke to effect the same movement of the absorption elements 12, 13 than if the cable were to be single-handedly to the north deck 6 walk. This is undesirable in connection with the length and stroke of the drive 29. This drive comprises a rack 30 extending longitudinally over the truss (Fig. 9) which can be moved back and forth with the aid of a gear (not shown). There is a pull-pressure tube 31 on the rack. The gear is in an i

Gear rack drive housing 32 and the adjustment stroke is at a maximum

i

bound by the distance between this rack drive housing 32 on the I

i '2 and the bearing housing 32A. Therefore, in the exemplary embodiment shown, an additional pulley 33 is made on the tensile pressure tube 31, which in turn cancels out this reduction in transmission: the pulley 33 is preferably designed horizontally and has

approximately the diameter of the width of the column 1, 3 (so as ka-I

troll 33 = center pull-pressure tube 31), whereby minimal extra moments are exerted on the pull-pressure tube 31. !

The drives 26, 29 are provided with drive motors, such as electric motors 34, 35. Although individual motors are protected by limit switches at the extreme positions of the racks 30 and 38 and with the control software working properly the 1 positions of motors is known and protected, a combination of motor positions can occur in some j situations in the event of disruption j! which can cause irreparable damage as a result of the motors 34; 35 work against each other. In at least one of the cables 15-17 i (preferably at a fixed point, such as in this case the end i of the cp cable 17 attached to the column 3), a tensile force sensor 17A is arranged which the motors both expansion with excessively high cable forces. A sensor per lifting section (ie 2 motors) is sufficient, because it is assumed that if the force in one cable becomes too high, it will become too high in all cables. In FIG. 2, the sensor 17A consists of an S-shaped force sensor provided with a strain gauge, which is mounted between the column 3 and the adjusting swivel. This location at the end of the cable 17 is convenient because it is a non-moving and non-rotating cable point and is as low as possible, making it easy to realize the electrical connection for the sensor 17A. [15] The movement mechanism 14 is closely connected in terms of drive

in the case of conventional or conventional mechanics in greenhouse horticulture I

(for example for the drive of screen installations or for the drive of hinged air vents). It is a mechanism! that must provide 2 degrees of freedom and therefore actually exists j

20 out of 2 drives. The two drives are so-called truss I

rail drives and are each provided with: a shaft 36, 37 in the longitudinal direction of the greenhouse (i.e. parallel to the cams / gutters), each shaft 36, 37 being driven by the associated electric motor 34, 35 (which is preferably in the middle of the shaft), around the compartment size (here 5.0 m, the shaft 36, 37 drives an angular transmission (gear in the rack 30 and 38, respectively), so these shafts 36, 37 serve several compartments ( for example 4 or 5 on one side of the motor 34, 35 and also 4 or 5 on the other side of the motor, so a greenhouse length of 2x (4 or 5) x 5 m j = 40 to 50 meters greenhouse length), these racks 30, 38 in turn drive so-called tensile-pressure tubes 31, 39 which lie on rack 2 in rack drive housings 32, 40 and bearing housings 32A, 40A (on one side of the shaft these tubes are subjected to tensile stress , on the other side of the shaft pressurized, hence the name pull-pressure tube), these pull-pressure tubes 31, 39 can operate multiple caps on the left and right of the axle simultaneously and (for example 3 to 4 | ί! 19 I

caps on one side of the axle and 3 or 4 caps on the other I

side of the axle, so a greenhouse width of 2x (3of4) x4m = 24 to 32 meters! greenhouse width).

In this way 40x24 to 550x32 = 960 to 1,600 m2 greenhouse with a motor 34, 35 (per degree of freedom) can thus be operated per motor in this example. The courses serve for cost reasons to be as large as possible. The size of the boxes is limited by the desired accuracy of the system. This conflicts with the possible building tolerances of the greenhouse, differences in thermal expansion of the greenhouse and tensile pressure tubes, torsion in the drive shaft, etc. In connection with this, the operated surfaces from the motor must be as "square" as possible; so the engine as much as possible in the middle of a lifting section. In practice, the courses will be approximately 1,000 to 2,000 m2 in size. These ratios 15 correspond reasonably with available shaft thicknesses and available! engine torque in relation to what is customary in greenhouse horticulture.

Finally, it can be noted that even with a horizontal adjustment of the tensile pressure tubes 31, 38 on the truss 2 of approximately half the cap size, the entire path of the focal line can be described. This is advantageous, because it allows the tensile pressure tube to be supported halfway through the cap (in the middle) by a bearing housing without coming into conflict with the cables. Also !'

at the edges of the greenhouse there is then no problem with "through the side

25 façade piercing "pull-pressure tubes. J

As can be clearly seen in FIG. 10 and 11, in the embodiment shown, the air vents 19 in the north deck 6 are designed as sliding windows, instead of "blow" air vents in conventional greenhouses. These sash windows have the advantage that a j

30 drop shadow of an open sky window on the next south deck I

5 is prevented, since the sliding window 19 does not protrude and j remains in the plane of the north deck. Furthermore, no operating mechanism for the air window 19 protruding far into the greenhouse is required. The operating mechanism 18 for the sliding window 19 can be kept very compact in the cover surface, as a result of which the absorption elements 13 and the operating technology 14 for this are not affected by this.

FIG. 12 shows a number of air vents 19 and the operating mechanism 18 therefor. The skylights 19 are via j! 20: connecting members 41 connected to below the north deck 6; toothed racks 42 which is slidable in the direction between cam 8 and trough 7 by means of a gearwheel 43 (Fig. 10, 11) accommodated in a gear rack drive housing 44. The toothed racks 42 and gearwheels 43 are in this embodiment two: bars 9 applied. The gears 43 in a deck 6 are interconnected by a shaft 45 which is rotatable with the aid of an electric motor 46 and can thus operate all windows 19 in the same north deck 6. The drive of the sliding air window can alternatively also be carried out with tension cables that wind on an axis with a sufficiently steep north-facing slope.

FIG. 10 and 11 further show that a rain cap 47 is arranged on the cam 8 above the opening for the sliding window 19. This is preferably transparent due to the minimal light interception and prevents rain from entering the greenhouse through a (partially) opened air window 19. The rain cap 47 is preferably made of plastic to minimize the thermal bridge effect. The ventilation from the ridge 8 of the greenhouse works well, but the controllability of the ventilation is difficult, in particular in the case of small openings due to the high pulling action. The rain cap 47 offers an improvement in controllability, because the passage is no longer determined by the opening between the top of the sliding window 19 and the cam 8 but by the opening between the outside of the sliding window 19 and the rain cap 47. By the Due to the special shape of the rain cover, this passage only slightly increases in the first part of the opening path of the window, whereby a much finer control is possible. The rain cap 47 thus acts as part of a control valve, the distance between the rain cap and the air window determining the air passage in a direction perpendicular thereto. The curved shape shown means that the opening in the first displacement of the air window 19 increases little and increases faster after the first critical start, whereby the rain cover gradually loses its function. As previously stated and as shown in FIG. 13 can be seen, there are two Fre- between gutter 7 and ridge 8 of each south deck 5; rapid lenses 10, 11. The Fresnel lenses 10, 11 are provided on one side with a profiling, for example in the form of grooves and knurls, see for example Figs. 14. The lens is designed so that the j j! ! 21! j ί

Fresnel profiling must be oriented upwards: this gives a higher efficiency of the lens and a higher (direct and diffuse) light transmission. This can be made understandable in that the light passes through a refractive surface 5 twice (non-perpendicularly) in this orientation, so that the profiling need be relatively less extreme: such a lens remains closer to a flat window in terms of shape. Because the lens is less extreme due to the two refractive surfaces, the lens has a better focus, in particular outside the design point (design point is perpendicular incidence, oblique light incidence outside the design point). Thus, designing the lens "upside down" is particularly useful in arrangements where the lens has a fixed orientation, such as in the present situation, fixed in the cover surface (in contrast to many applications where the Fresnel lens moves with the sun in 1 or 2 directions) and the light always nearly coincides with the design point)

As shown in FIG. 13, the Fresnel lenses 10, 11 are constructed from a number of lens elements A and B. These are formed by injection molding. This makes the lens elements relatively small, so that the mold costs can be kept under control.

In the exemplary embodiment shown, the lens elements A and B consist of square pieces of ± 40 x 40 cm. Use can herein be made of only two molds (casting molds) or, for example, also one mold with different inserts) in the form of a half middle part A, A 'and a half outer part B, B'. The lens elements A, A 'and B, B' can be of the same design, that is to say they are arranged in mirror image to form the symmetrical lens. A pair of ± 160 cm x 40 cm can thus be formed with two pairs of two different lens elements i A / A 'and B / B'.

Various (relatively small) lens elements 30 have been chosen to limit the mold costs. By for different I

choosing lens elements can also be the cartel height and width per |

lens element can be optimized, so that material use and I

efficiency per lens part can be balanced. In the case shown, the lens element A may become thinner than the lens element B where the lens must be "stronger" to displace the light.

bending, which means that the cartel height and therefore the plate thickness must be greater. Each lens element A, B is provided with an op-1 around the circumference

standing edge or ledge 48, which is preferably both upwards and |

22 I

protruding downwards. Furthermore, near the corners of each lens element a leg 49 is provided, just inside the ledge 48. j

The ledge 48 has a number of advantages. First, it prevents the flat lens element from warping during injection molding and cooling thereafter. Because the ridge extends both above and below the lens element (so that the Fresnel lens connects in the middle), it is possible to easily fit the lens elements in a double-glass pane 50, so that a construction j

of 3 layers with air in between. This leads to a large I

10 delicate U-value of the glass pane. The disadvantage of the extra jade layer of the 3 layers is then converted into an extra advantage. In addition, the ledge ensures that the scratch-sensitive plastic lens surfaces lie completely free of the glass and therefore cannot be damaged over time due to friction with the glass plates.

The upright ridge 48 and the legs 49 also ensure the mutual positioning of the lens elements A, B between the glass plates 51 of the glass pane 50: they cannot pass each other when the glass pane 50 is closed if the space between the glass plates is closed. 51 is smaller than twice the combined height of the ledge 48 and the leg 49. The legs 49 have between the glass! plates 51 therefore also the function of spacer: by applying j of the legs 49 the ledge 48 can be lowered, thereby saving material j: the total ledge height + leg height ensures the confinement of the lens elements A, B in the glass pane 50 at minimal use of materials.

The main function of the legs 49, however, is that the lens elements A, B become easily stackable (see Fig. 18), so that the lens elements can be injected with a robot after injection molding.

30 are stacked instead of a person on the injection molding machine. A further advantage is that there is no expensive packaging for the! lens elements are required: the lens elements A or B lie separately from each other through the legs 49 and ridges 48, so that the surfaces i of the lens elements lie free from each other. In the case of ordinary flat lens elements, they must be provided with a protective film on both sides for protection against scratches. The ridges 48 and legs 49 thus also serve as a spacer during transport and storage. j 23 j

The lens elements A, B are on their opposite sides, which in practice point in the direction parallel to the cam 8 of the greenhouse, provided with mutually fitting puzzle piece or dovetail-like, that is to say pull and preferably also j 5 sliding, connecting means 52, 53 (see Figs. 15-17),

by the lens elements in a row parallel to the cam 8 (see Fig. "13) being connected to each other non-slidably and rotatably.

The connecting means 52, 53 do allow a slight angle of rotation transversely to the surface of the lens elements. The rows of 10 lens elements A, A ', B, B' are, in the direction parallel to the cam 8 of the greenhouse, freely sliding with respect to each other (they only have to lie well against each other, but this is done automatically by the gravity component in the south-facing slope α j

(Fig. 14) down). I

As previously indicated, the lens elements A, B are placed inside conventional insulating double-glass panes 50, which can be provided with an anti-reflex coating at least on the facing, but possibly even on the four surfaces. and for example glass thicknesses of 4 mm with a spacing of 16 mm. Because the surfaces of the lens elements A, B and glass plates 51 are separate from each other and can therefore expand and shrink freely relative to each other, it is not necessary to laminate the lens elements on one of the glass plates 51, so that no delamination problems can arise and 25 costs are saved. The surfaces of the lens elements A, B can also be provided with an anti-reflection coating. j

The panes of the north deck 6 are preferably diffuse

so that any light falling on the north deck enters the greenhouse diffusely. In the case that double-glass is used on the north deck, the upper surface will preferably be I

of the glass plate on the inside / bottom side are made diffuse. For example, all the light entering the greenhouse is diffuse. After all, it; light entering the greenhouse via the Fresnel Lenses 10, 11 is also diffuse when it reaches the ground of the greenhouse. An anti-reflective coating 35 will usually not be applied to the panes of the north deck 6 because any light reflected from the panes of the north deck 6 will still enter the greenhouse via the south deck 5.

24 I

As mentioned earlier, the greenhouse cover is a so-called Ven lodek: apart from the aluminum glass supports (bars 9), the gutter | 7 and the cam 8 no longer have any construction in the deck. A choice for a veneer deck is based on the shadow formed by the deck on the absorption elements 12, 13 and on PV cells that form part of it. With a Venlo deck (in contrast to a wide-skinned deck construction) the shadow pattern is very uniform and repetitive) (each rod 9 gives a shadow line at the same mutual distance), making it easier for the electrical circuitry of the PV cells to move towards it. to vote (shading of PV cells is a major problem with PV installations). It is then possible to connect the PV cells in one PV module with the length of the center-to-center distance of the rods (i.e. for example 1,250 mm) in parallel with each other and then to connect these modules in series with each other). ! FIG. 19 - 22 show one of the absorption elements designed on that basis. The absorption element comprises a water-cooled rectangular or square tube 55, preferably stainless steel, which provides structural stiffness and strength (around the compartment size of, for example, 5.0 m suspended from the adjustment cable described previously). This tube 55 also serves as a conductor for the cooling water (so 2 functions). This tube 55 is welded in place, i.v.m. ! dimensional accuracy, straightness and maximum hydraulic capacity with minimum resistance. j '

On top of the tube 55, PV modules 56 with PV cells 57, in the form of a PV laminate, are provided at work; preferably with the aid of a heat-conducting self-adhesive tape. 58. The top side of the PV laminate consists of preferably hardened, non-reflective glass, and the bottom side is preferably of anodized aluminum plate in connection with the maximum thermal conductivity. and electrical insulation. In between are the PV cells 57 which are suitable for 20 to 30 suns, or a radiation density of 2 to 3 W / cm 2, and which are laminated with preferably heat-conducting (electrical insulating) tape or, for example, by a zinc oxide additive, modified (heat-conducting) EVA film (between at least the PV cells and the aluminum back plate) and standard EVA film, silicone rubber, casting resin or other encapsulating material above and next to the PV cells.

| [i i 25! i

Current-conducting connection poles 59 of the PV modules 56 in the form of contact strips are electrically connected to work. coupled by heavy, solid current conductors 60. These are preferably formed from aluminum. This aluminum can be provided with a protective coating or can be tinned or silver-plated.

This protection can optionally only be provided at the location of the electrical connection terminals 59; for example via partial; tinning by masking, see the shaded areas 60 '! on the current conductor 60 in FIG. 21. The current conductors 60 have a length of 2x the module length, thus 2x the center-to-center distance of the cover bars 9.

The electrical coupling between the connection poles 59 of the PV laminate 56 and the heavy current conductors 60 is effected by a! terminal or push button connection. For this purpose, the heavy electrical current conductors 60 are placed in an (injection-molded, in order to limit the costs that lengths can be 30 to 40 cm, preferably a partial multiple (or divisor) of the PV module size) plastic holder 61 which is also electrical insulator serves. The thin terminal poles from the laminate are laid against the current conductor 60 per potential (+ and -). With a loose or hinged lid 62 (can also sit on the side) and a resilient rubber insert or (preferably) molded plastic leaf spring 63 per contact point or location, the clamp / push contact is realized by the plastic lid 62 or the side can be pushed shut in snap fasteners 64 25 (wedge-shaped with hook edge, therefore also open again for maintenance / disassembly). The connected thin terminal poles 59 become; then folded under the PV laminate 56, next to the tube 55 (see Fig. 22). An electrically insulating profile 65A is slid over the module edge and the folded-over terminal poles 59. If the shell 65 is not conductive, such an insulating profile is not necessary. ;

As shown in FIG. 19, the aluminum shell 65 can be demountably clicked onto the tube 55 by means of holes 65 'in the middle of its underside on plastic click profiles 55A. When the aluminum shell 65 is clicked onto the plastic click profiles 55A (and the plastic click profile 55A thus protrudes through the hole 65 '), this can only be done at the bottom, because the sun cannot get there.

Otherwise the concentrated sunlight would shine on the plastic and melt it.

l

26 I

! j

As shown in FIG. 20, the PV modules 56 are arranged alternately (rotated 180 ° relative to each other) so that! all PV modules 56 can be identical. The PV modules 56 are therefore not made rotationally symmetrical, but always have the + and - sides on both sides of the PV cells 57 (i.e. on either side of the laminate) on the same side. By obliquely modifying the ends 66 of the PV modules to such an extent that a trapezoidal PV module 56 is created, it is not possible to mount a PV module 56 incorrectly on the tube 55 and the - closing poles 59 are automatically properly aligned. Of course, other shape adjustments are also conceivable to impose the alternate placement of the PV modules. The edges of the PV modules 56 which face one another will then have a parallel shape that extends from a straight line perpendicular to the longitudinal edges of the modules! deviates. For optimum use of the water surface from which they are formed, the PV cells 57 may be cut obliquely and preferably the slope of the edges of the PV modules 56 is the same as the slope of the PV cells 57 ( see Fig. 19 and 20), so that the surface of the PV module 56 can be optimally occupied by the PV cells 57.

As stated, the PV cells 57 are connected in parallel, while the PV modules 56 are connected in series. By the essay!

and interconnection of the modules via the current conductors I

60 no plug connections are required between the modules 56 I

which results in a considerable cost saving in view of the large flows. Because the length of the modules corresponds to | the center-to-center distance of the glass rods 9 each PV module 56 will receive the same amount of shadow and this shadow has no negative effect on the series connection between the modules. The PV module can also be made with L = 2x) center-to-center distance or with 1, = ½ center-to-center distance, so it is basically a question of connecting a group of PV cells in parallel with a length equal to the rod-center. center distance. |

The snap-on attachment of the current conductors 60 simplifies assembly to the work, so that hardly any assembly errors will occur. j

As shown in FIG. 23 in particular, it is absorption | element provided with a second concentrator 67 with oblique mirrors 68 which connect to the PV cells 57 on both sides and concentrate the sunlight further on the PV cells 57. This 2nd concentrator 67, which is fixedly mounted with respect to the absorption element, is possible because the upper surface of the absorption element 12, 13 always remains oriented perpendicular to the light beam due to the chosen movement mechanism. As a result, the fixed 2nd concentrator 67 will naturally always be reasonably optimally oriented with respect to the light beam. The triangular shapes (this may also be a concave or a convex mirror j) of the 2nd concentrator 67 creates space between the PV cells 57 and the module edge and therefore space for the realization of the connection between the PV cells 57 and the terminal poles 59 and current conductors 60. The connection of the current conductors 60 is constructed in the space below the PV laminate 56 below and next to | the PV cells 57 under the mirrors 68 of the 2nd concentrator 67. The space under the mirrors 68 is additionally used to provide the required achieve the minimum distance between the PV cells 57 and the edge of the laminate 56 due to unwanted entry of moisture into the laminate that could attack the cells. This space is also required to be able to isolate the absorption element with a considerable thickness. The space under the mirrors 68 is thus effectively used for multiple purposes, so that the mirrors are also useful from this point of view. The terminal poles 59 of preferably tinned copper leave the PV-j laminate 56 as quickly as possible (due to minimization of costs). The terminal poles 59 can be soldered or glued to the PV cells 57 with electrically conductive glue. j

In the absorption elements, the various functions j are separated as much as possible from each other: structural strength and | rigidity, PV cells laminate, water cooling, electrical current drainage are mainly achieved by various elements. j

The absorption elements 12, 13 can also be used as daylight control by moving the absorption element 12, 13 from the focal line of the lenses 10, 11, whereby a part of the light beam will pass along the absorption element 12, 13 walk. This can cause exposed and shaded stripes and to counteract this, each absorption element 12, 13 is provided on both sides with a scattering glass 69, which can scatter the light from the light beam in such a way that the light and dark 28 spots are as much as possible. be settled. Instead of scattered glass, other light-scattering elements, such as Fresnel lenses, can also be used.

The aforementioned 2nd concentrator 67 is a set aluminum 5-mirror profile (provided with a PVD multi-layer structure), which also extends downwards along the side of the absorption element, so that the light is somewhat "beside" (but against) the absorber. The tie element falls, the greenhouse is reflected back as much as possible, so that none of the light is lost and everything is used in a useful way. This mirror can also cooperate with (if used) the scattering glass 69. In both situations! therefore cooperated with the daylight control function. |

FIG. 23 shows the suspension of one I in more detail

of the absorption elements 12, 13 on one of the r-cables 15, 16. In this case, this suspension comprises an inverted V-hook 75, the bent free ends of which hook into the eyes of a yoke 76 that the absorption element 12, 13. The V-hook 75 is preferably made of rigid construction material (in this case solid 4 mm). This has the advantage that the inverted V-hook j can also absorb small compressive forces, which is important if j wants to tilt the absorption element due to gravity (in Fig. 3) "counter-clockwise". If the inverted V-hook were to consist of a cable, then the right cable could hang limply in that case. The hook 75 has 2 functions: to keep the absorption element 12, 13 up, while leaving as little shadow as possible; j falls on the absorption element (hence the wide legs) and j

stabilizing the absorption element (hence the wide legs). The rigid, tailor-made suspension, in this case in J

the shape of the inverted V-hook 75 also facilitates the mounting

30 tons of the absorption elements on the cables 15, 16. J

In FIG. 24 and 25, a further aspect of the invention is shown in the form of a sun tracking system 70 for the movement mechanism 14 of the absorption elements 12 and 13. The tracking system 70 in this case comprises two rows of sensors or detectors; 35 detectors 71 and 72. The row of sensors 71 is at a distance | from 2-10 cm above the absorption element 13 and the row of sensors 72 j at a distance of 10-20 cm above the absorption element 13. Both! rows of sensors 71 and 72 are not placed one above the other but are located on the horizontal plane (in the direction parallel to 29 j the length of the absorption element 13) about 30 cm (or rod) center distance, in this example 1 , 25 m) side by side. This is to prevent any shadow on the bottom row of sensors 71 (or not to influence the j fill factor of the PV cells too much). Each row | 5 71, resp. 72 includes around 10-20 light-sensitive sensors. These can be, for example, photodiodes, phototransistors or photosensitive resistors (LDR). One row of light-sensitive sensors can measure differences in light intensity. When the absorption elements 12, 13 are close to the relevant focal point or the focal line on the basis of calculated values from the sun position, points C and D can be determined from the signals of the lower row of photosensitive sensors 71 from light intensity differences.

Similarly, the top row of photosensitive sensors 72 points A and B can be determined from differences in light intensity. As a result, the boundary of the focusing light beam L is known. When the points ABCD have been determined from the light intensity differences, the position and the slope of the boundaries of the light beam L can be determined with (computer) calculations. These limits indicate the shape of the converging rays of light to the focal line. ; With the details of the position and the slope of the boundaries of the light beam L and the information of the width of the focal line, the position of the focal line can then be determined.

The rapid determination of the position of the focal line is important in order to prevent the absorption elements 12, 13 from moving again when searching for the focal line. This also prevents energy loss due to the unnecessary energy consumption of the! motors of the drives of the movement mechanism 14 and j because the absorption elements 12, 13 are not positioned in the focal line. isitioned.

With larger angles of incidence, the light-dark transitions at the boundaries of the light beam L will be less sharp. In that case the correct position of the boundaries of the light beam L will be determined from the intensity variation of the two rows of sensors. If necessary, the sensor can be calibrated for this purpose with the measurement of the power generated. j

The software of the computer included in the tracking system is learning and the positions reached are stored. As a result, the tracking system 70 can always be effective by adding information. get far! 30 yrs

The invention is not limited to the exemplary embodiments shown in the drawing and described in the foregoing, which can be varied in various ways within the scope of the invention. Thus it is possible to increase the number of loans! between the gutter and ridge, for example to 3 or 4, whereby the number of absorption elements also increases to 3 or 4. In that case, it is not necessary to return the lower absorption elements via a pressure rigid connect two absorption elements to the upper connection, but a cable connection would therefore be possible if the kabel-cable on the pressure-rigid | connection between the upper two absorption elements. Furthermore, it is possible not to use linear Fresnel lenses, but non-linear Fresnel lenses (in particular circular Fresnel lenses, with point concentration). The pulleys of the r and φ cables must then be placed around an (extra) axle!

able to turn (to give these cables space to turn "left" and "right" towards the end walls) and somewhere in the roof length or on the facade there will be an additional adjustment mechanism I

20 that the assembly of absorption elements can translate in the direction parallel to the ridge of the deck. The point of engagement of the φ-cable near the cam will have to be moved!

to the point at the upper pulley 23 of the I

highest r cable. The pressure-rigid connection then does not have to be hinged with the cooling housing of the absorption elements, which then becomes a sort of supply-return line (A round or square PV cell with heat exchanger, alias module, hinges above it (or rather the cooling water pipe hangs underneath).

Although the invention has been described with reference to a Venlo greenhouse with an asymmetrical hood, the invention is also applicable to greenhouses (Venlo, wide hood or another type) with! symmetrical caps. The invention is furthermore not limited to the use in horticultural greenhouses, the invention is also applicable in other buildings with a roof, such as office buildings, homes 35 and the like, wherein the lenses can be built in; (sloping) roofs of atriums, conservatories and the like, which therefore | mainly to the south (or north to the southern hemisphere). The shadow patterns can be set here by i

elements other than glass rods are caused. Of course I

| In this case, only a single (Fresnel) lens with an associated absorption element can be used. The different characteristics of the greenhouse can also be realized in such structures. ï i

Claims (15)

32 I CONCLUSIONS j A horticultural greenhouse of the "Venlo" type, with a skeleton for supporting at least one roof construction, which roof construction is provided with at least one, preferably! asymmetrical hood with a substantially south-facing south deck and an adjacent north deck, which north deck and south deck are bounded on one side by a gutter and on an opposite side are bounded by a higher ridge, the north deck being provided of windows and aeration windows! and the south deck is provided with at least two, preferably linear, Fresnel lenses placed between the gutter and ridge, each with | associated and below-arranged absorption elements, which are adapted to follow the sun position with at least two degrees of freedom with the aid of a movement mechanism coupled to the absorption elements, which mechanism is provided with traction cables, the absorption elements are suspended from adjustable suspension cables (r-cables) that of the absorption; elements extend at least approximately along the axis of the associated lenses to the south deck and therefore adjust the distance to the lenses on adjustment, while at least another adjustable cable (φ-cable) extends to the north deck and on adjustment the angle cp between the vertical and the r-cable, characterized in that the absorption elements are connected to each other by a pressure-rigid connection and the kabel-cable engages the unit at a location at a distance from the absorption element that is closest to the north deck. 2. Horticulture greenhouse according to claim 1, wherein the β-cable engages the pressure-rigid connection at a location in the vicinity of the absorption element furthest away from the north deck. 3. Horticulture greenhouse according to claim 1 or 2, wherein the φ-cable on the north deck effectively engages in such a place that in all positions of the absorption elements the angle between the φ-cable and the r-cables is approximately 140 ° at most and the maximum angle between the horizontal and the kabel cable is approximately 50 ° i ί 5 ii 33! Horticulture greenhouse according to claim 2 or 3, wherein the cp cable runs from a position near the cap of the cap to a pulley on the unit of the absorption elements and extends to a lower location on or below the north deck . i The horticultural greenhouse according to claim 4, wherein the p-i cable extends to a pulley on a column of the skeleton below the north deck. ; 6. Horticulture greenhouse as claimed in any of the foregoing claims, wherein the absorption elements are adapted to always be directed in the direction of the center of the associated Fresnel lens. 7. Horticulture greenhouse according to claim 6, wherein the absorption elements are each separately attached to one of the r-cables and rotatably connected to the pressure-rigid connection between the absorption elements, and / or wherein the absorption elements are connected by means of a rigid and downwardly extending transversely to the length of the absorption elements, the suspension member is connected to the relevant r-cables. 8. Horticulture greenhouse as claimed in any of the foregoing claims, wherein drives for the r and kabels cables are each attached to a horizontal frame of the skeleton. The horticultural greenhouse according to claim 8, wherein the cp | cable at the horizontal truss through 180 degrees is diverted around a pulley movable parallel to the φ-cable and connected to the associated drive. j 10. A greenhouse according to any one of the preceding claims, wherein in a direction parallel to the ridge of a roof a | number of horizontal trusses, while at least | a part of the trusses, and preferably with each truss, the absorption elements are provided with r and kabels cables and associated drives on the horizontal trusses, the | drives of a number of horizontal trusses are mutually! coupled and adjusted with a single drive motor. j 11. Horticulture greenhouse as claimed in claims 8 or 9 and 10, wherein the drives on the horizontal trusses are equipped with racks that are connected with the associated cables, and with gears that engage with the associated racks and mutually are coupled by a torsionally rigid shaft j which is rotatable by the relevant drive motor. i | 34 i A greenhouse according to any one of claims 8 to 11, wherein the greenhouse comprises a number of connecting caps and the drives for the r and φ cables of a number of caps are mutually coupled. j A horticultural greenhouse according to any one of the preceding claims, wherein the ratio of the width of the Fresnel lenses in the direction between gutter and ridge and the focal line (focus) distance is at most approximately 0.85, and preferably between approximately 0.66 and 0.82. A horticultural greenhouse according to any one of the preceding claims, "10, wherein the Fresnel lenses, at least in the direction between gutter and ridge, of a number formed with the aid of casting molds; elements is formed. ! The horticultural greenhouse according to claim 14, wherein the Fre-fast lenses are formed from a number of pairs of elements which! 15 are mirrored with respect to the line of symmetry of the Fresnel lens. j 16. A greenhouse according to any one of the preceding claims, wherein the Fresnel lenses are grooved on that side of the lens which faces upwards. The horticultural greenhouse according to claim 16, wherein the Fre quick lenses are placed between glass plates of a window. A horticultural greenhouse according to claim 14 and 17, wherein a number of elements of a Fresnel lens are placed between two glass plates, which elements are at least at the top and bottom; The edge is provided with a ridge projecting transversely to the element, which protruding preferably to the bottom and top. The horticultural greenhouse according to claim 18, wherein the ele-; moldings are formed by injection molding and at the edges, preferably near the corners, are provided with stacking members, such as; 30 protruding legs on at least one side for cooperation with the ridges. j 20. A greenhouse according to any one of claims 14-19, wherein the Fresnel lenses in the direction parallel to the ridge! is formed from a plurality of elements and the elements of the Freelift lenses are formed on their opposite side edges with positive-fitting connecting members, such that adjacent elements in the direction j parallel to the cam are tensile connected to each other. y y} 35 y A greenhouse according to any one of the preceding claims, wherein the aeration windows on the north deck are designed as sliding windows. j 22. Horticulture greenhouse according to claim 21, wherein the drive for the aeration windows is attached to the north deck. 23. Horticulture greenhouse according to claim 21 or 22, wherein the north deck at a location above the opening of the sash windows is provided with a (transparent) rain cover that extends obliquely downwards from the north deck at an angle with the north deck 10 to a free end . The horticultural greenhouse according to claim 23, wherein the rain cover is curved and the angle of the rain cover with the north cover increases in the direction of the free end. i A greenhouse according to any one of the preceding claims,! Wherein the angle of the south cap with the horizontal is between 10 ° and I 40 ° and is preferably approximately 30 °, and the north cover is at least approximately perpendicular thereto. 26. A greenhouse according to any one of the preceding claims, wherein the absorption elements are provided with a number of PV modules with PV cells. i The greenhouse according to claim 26, wherein the PV cells within a PV module are connected in parallel and the adjacent PV modules are connected in series. 28. Horticulture greenhouse according to claim 26 or 27, wherein the absorption elements are designed with carrier profiles welded together in work, on which the PV modules are placed, preferably with the aid of adhesive strips. j 'j 29. Horticulture greenhouse according to one of claims 26 - 28, wherein the adjacent PV cells within a PV module 30 are provided with connection poles protruding transversely to the length of the PV module, wherein adjacent PV modules are alternately so that, with adjacent PV modules, plus poles of one PV module protrude to the same side as the corresponding minus poles of the other PV modules and thus a | The length of two adjacent PV modules is a continuous conductor with all the associated and outwardly projecting poles of the adjacent modules, whereby the PV modules are connected in a conductive manner in series. j 36 30. A greenhouse according to claim 29, wherein the current conductors are attached to the PV modules by means of click profiles, preferably in that each pole and the current conductor are clamped against each other by the click profiles. j The greenhouse according to claim 30, wherein the snap profiles are provided with pressure members for keeping the current conductors in contact with the poles. j 32. Horticulture greenhouse according to any of claims 26-31, wherein at least a number of the PV modules have a parallel shape deviating from a perpendicular line at their edges that face each other, for example are cut obliquely in parallel. " 33. A greenhouse according to any one of the preceding claims, wherein the absorption elements are provided on either side with slightly scattering elements, such as scattering glass or Fresco | nel lenses for daylight control, and / or wherein the absorption elements are provided with a 2nd concentrator with I mirrors that reflect the light from the Fresnel lenses to the absorption element, which 2nd concentrator can run downwards and, if desired, with the light scattering elements can work together. A horticultural greenhouse according to any one of the preceding claims, wherein the north deck is provided with windows with at least one diffuse surface. I 35. A greenhouse according to any one of the preceding claims, wherein 2 Fresnel lenses are arranged between the gutter and ridge of the south deck and therefore 2 absorption elements and wherein the 1 ratio of the distance between the gutter and the truss and the length of the focal length is between 0.6 and 1.1 . | 36. A greenhouse according to any one of the preceding claims, wherein drives for the movement mechanism for the absorption elements are controllable by a solar tracking system, which tracking system is provided with at least two rows of: light-sensitive sensors which are substantially transverse to and in the frame. light beam, with the rows moving in different directions. positions to the lens and of measuring means capable of measuring the amount of light received from the sensors and calculating means which from the light measurements in the two rows are at least in the direction of the light beam and preferably also the distance | 37; be able to calculate from the focal line to the lens, and the tracking system can thereby control the drives for keeping the absorption elements in the focal line. j 37. A greenhouse according to claim 36, wherein the rows of photosensitive sensors are offset relative to each other in a direction parallel to the focal line, preferably over a distance of a number of times more than their mutual distance in the direction perpendicular on the lens. I 38. Horticulture greenhouse according to 36 or 37, wherein the one row of light-sensitive sensors at a distance of approximately 2 - 10 cm above the absorption elements and the other row of sensors are placed at a distance of 10-20 cm above the absorption elements. 39. Lens system for use in roof systems, provided with two spaced-apart glass plates with! between them is a Fresnel lens, which is provided with a large number of parallel grooves, wherein the Fresnel lens is formed at least in a direction perpendicular to the grooves of a number of elements formed with the aid of casting molds. [ A lens system according to claim 39, wherein the Freelift lenses are formed from a number of pairs of elements which are arranged mirrored with respect to the plane of symmetry. I 41. Glass pane with lens system for use in roof systems, provided with two glass plates mounted at a distance from each other, with a loosely arranged Fresnel lens between them, which is provided with a large number of parallel grooves which adhere in the position of use of the glass pane. located at the top of the j Fresnel lens. j 42. Structure with at least one roof structure in front Fig. 30 shows a number of hoods with a substantially south-facing sloping south deck and an adjacent north deck, wherein at least the south deck is provided with double-glass panes with two spaced-apart glass plates, of which only on the south deck at least the inner surfaces facing each other and preferably all surfaces are provided with an anti-reflective coating. j 43. Horticulture greenhouse with a skeleton for supporting at least one roof construction, which roof construction is provided with at least one on one side through a gutter and on one side 38. Opposite side by a raised ridge bounded deck, which is provided with windows and aeration windows, characterized in that the aeration windows on the deck are designed as sliding windows, wherein preferably the drive for the aeration windows on this deck deck is attached. 44. Horticulture greenhouse according to claim 43, wherein the roof construction is asymmetrical with a first deck, in particular a south deck, and a second, slanted and shorter deck, in particular a north deck, wherein the aeration windows designed as a sliding window in the second cover are fitted. j A horticultural greenhouse according to claim 43 or 44, wherein the deck is provided at a location above the opening of the sliding windows with a (transparent) rain cover that is from the deck; sloping downwards at an angle with the deck extends to a free end. i 46. Absorption element for collecting sunlight through the roof of a building, which roof causes a repeating shadow pattern, which absorption element is provided with a number of PV modules with PV cells, the length of the PV - 20 modules correspond to those of the shadow pattern, wherein the PV cells within a PV module are connected in parallel and the adjacent PV modules are connected in series. | { 47. Absorption element for collecting sunlight, provided with a plurality of PV modules arranged one behind the other, each formed from a number of PV cells, which modules preferably work on a support of the absorption element. are arranged, wherein at least a number of the PV modules have a parallel shape deviating from a perpendicular line at their edges facing each other, for example, cut obliquely in parallel. j The absorption element of claim 47, wherein each PV module is provided with a number of consecutive; placed PV cells, wherein at least a number of the PV cells are cut at the opposite edges obliquely parallel, in particular parallel to the oblique edges of the PV modules. 49. Building with at least one roof construction, which roof construction is provided with at least one roof, which south deck is provided with at least two Fresnel lenses, with below 39 absorption elements arranged for following the position of the sun with at least two degrees of freedom with the aid of a movement mechanism coupled to the absorption elements, which mechanism is provided with tension cables, the absorption elements being suspended from adjustable suspension cables (r-cables) which extend from the absorption elements at least approximately along the axis of the associated lenses to the south deck and therefore adjust the distance to the lenses upon adjustment, | while at least one other adjustable cable (φ cable) to! 10 extends north and adjusts the angle φ between the j vertical and the r-cables when the adjustment is made, characterized in that the absorption elements are connected to one unit by a rigid connection and the φ-cable engages on the unit on; a location at a distance from the absorption element that it; 15 is located closest to the north side. The structure of claim 49, wherein the kabel cable I engages the pressure-rigid connection at a location in the vicinity of the absorption element furthest away from: the north deck. j 51. Building according to claim 49 or 50, wherein the φ- | cable runs from a position near the top of the south deck to a pulley on the unit of the absorption elements and extends to a lower location on the north side. j 52. Building with at least one roof structure, which; 25 roof construction is provided with at least one roof with a roof south-facing south-facing, substantially south-facing, provided with at least one Fresnel lens, with an ab-mounted underneath; sorption element adapted to follow the sun position with at least two degrees of freedom with the aid of a movement mechanism coupled to the absorption elements, which mechanism can be controlled by a sun tracking system, which tracking system is provided with at least two rows of photosensitive sensors j which extend substantially transversely to and in the light beam, the rows being arranged at different distances from the lens, and of measuring means which can measure the amount of light j received from the sensors and calculating means which come out of the light measurements in the two rows can at least calculate the direction of the light beam and preferably also the distance of the focal line or focal point, and the tracking system thereby calculates the j 40 I drives can be used to keep the absorption elements in the focal line or focal point. 53. A structure according to claim 52, wherein the rows i of photosensitive sensors are offset relative to each other in a direction parallel to the focal line, at j. preferably over a distance of a number of times more than their mutual distance in the direction perpendicular to the lens. I 54. Structure according to claim 52 or 53, wherein the | one row of light-sensitive sensors at a distance of approx. 2 - 10 cm above the absorption elements and the other row of sensors! j is placed at a distance of 10-20 cm above the absorption elements. ; 55. Solar tracking system for use in the structure according to one of claims 52-53. 15 I fs È